Prevalence and comorbidities associated with hidradenitis suppurativa in Korea: a nationwide population-based study

Background: The prevalence of hidradenitis suppurativa (HS) in Asia is unknown. The associations between HS and other autoimmune disorders have rarely been reported. Objective: We sought to determine the prevalence of and diseases associated with HS using the National Health Insurance (NHI) database. Methods: We examined Korean NHI claim database data from 2007 to 2016. We enrolled all patients with HS and age- and sex-matched control subjects without HS. We estimated the period prevalence of HS and associated comorbidities in Korea. Results: We identified 28 516 patients with HS (61.3% males and 38.7% females). The period prevalence rate was 0.06%, 55.8 patients (95% confidence interval 55.1–56.4) per 100 000 persons, and the female-to-male ratio was 1 : 1.6. HS patients were at significantly increased risk of rheumatoid arthritis, ankylosing spondylitis, type 1 diabetes, ulcerative colitis, type 2 diabetes, hypertension, hyperlipidaemia, acne conglobata, pilonidal cysts, psoriasis, pyoderma gangrenosum, alopecia areata and vitiligo. Conclusion: The overall prevalence of HS in Korea was lower than that in Western populations, and male patients predominated.